IRS1 and obesity due to melanocortin 4 receptor deficiency: This association became statistically significant when analyses were repeated with additional adjustment for BMI (overall OR: 0.88; 95%CI: 0.80–0.96, p = 0.006), although since there was no relationship of this SNP with BMI, and GWAS of genetic variants influencing BMI, obesity and related phenotypes have not identified IRS1 as a BMI related gene [8], the mechanism of this is unclear.